Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant zinnia in Colusa by reviewing the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Zinnia require warm weather which tells us that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant zinnia in Colusa is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably September. If you wait any later than that and your zinnia may not have a chance to really do well. Starting your zinnia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Colusa. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Colusa is just an average the actual date of last frost changes from year to year. Half of the time in Colusa it frosts late in the year after February 15 so make sure that you are ready to protect your zinnia in the event of one of those late frosts.

USDA Zone Info for Colusa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Colusa

You may be interested in your other planting guides for Colusa.